Refinement of Nd-422 particles in Nd-Ba-Cu-O bulk superconductor

Author

Iida, K. ; Yoshioka, J. ; Murakami, M.

Author_Institution

Superconductivity Res. Lab., Int. Superconductivity Technol. Center, Iwate, Japan

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

3529

Lastpage

3532

Abstract

We have investigated the effect of oxygen partial pressure, the initial composition, and the addition of CeO₂ and/or Pt on the grain growth of Nd₄Ba₂Cu₂O₁₀ (Nd-422) in the Ba-Cu-O liquid. Logarithmic plots of the mean diameter of Nd-422 under various oxygen levels as a function of the holding time showed the power law behavior with the slope of 1/3, which suggested that the grain growth of Nd-422 could be explained in terms of the Ostwald ripening theory. A reduction of oxygen partial pressure, the shift of the initial composition toward Ba-rich direction, and a combined addition of Pt and CeO₂ could suppress the coarsening of Nd-422. Furthermore, a combination of these techniques was found to be effective in refining the Nd-422 in the Nd-123 matrix, which led to an enhancement of J_c values

Keywords

barium compounds; cerium compounds; critical current density (superconductivity); grain growth; grain refinement; high-temperature superconductors; neodymium compounds; platinum; stoichiometry; Ba-Cu-O liquid; CeO₂; J_c; Nd-422 particles; Nd-Ba-Cu-O bulk superconductor; Nd₄Ba₂Cu₂O₁₀; NdBa₂Cu₃O₇:CeO₂,Pt; Ostwald ripening; Pt; composition; diameter; grain growth; holding time; logarithmic plots; oxygen partial pressure; power law behavior; refinement; Crystal microstructure; Furnaces; Laboratories; Magnetic materials; Powders; Superconducting magnets; Superconducting materials; Superconductivity; Telephony; Temperature;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919825

Filename

919825